It has in common with Kokoda a role in some of the most crucial moments of the Second World War, including the Battle of Wau, where Allied forces fought the Japanese to a standstill.

But as he struggled across the huge mountain backbone of our nearest northern neighbour, Ray discovered adventure, scenery and culture shock on a scale reminiscent of Lord of the Rings.

Relics along the way included dumped mortars, heavy machine guns from both sides and the country's best preserved Second World War plane wreck - a shot up B17 Flying Fortress.

Kokoda is "still a fine walk," tour organiser James McCormac wrote in that pamphlet that caught Ray Gresham's eye. "But the Black Cat/Bull Dog track is "more challenging... a real adventure".

"More challenging" turned out to mean "dodgy river crossings, deep mud, leeches, torrential rain" and all participants "physically shattered" by the end.

Of all this, Ray had fair warning when he set out on October 10 for 12 days of slipping, sliding, walking, hobbling and hanging on for dear life, as he retraced the steps of the soldiers who slowed the Japanese advance from the beautiful beachside village of Salamaua, on the northern coast near Lae, to the critically important mountain airstrip at Wau.

Dumped mortars from the Second World War.

If the Japanese had got past there, they would have had a made road (now eroded and landslip damaged to the point of being a narrow foot track) to the south coast at Terapo.

More strategically important still was the airstrip, which would have provided a base for aerial bombardment of Port Moresby.

The airstrip is on a 10-degree slope, with mountains all round, one of PNG's infamous no-second-chance landing fields - made even more tricky by Japanese soldiers shooting from the end of the airstrip.

Planes bringing up to 50 soldiers would lose two or three as they attempted to get off.

Then the pilots would have to turn around and take off, carrying the wounded, right in the face of the enemy guns.

Ray Gresham's adventure was not quite so death defying, but it was certainly a challenge - one accompanied by some of the most stunning and difficult landscape imaginable.

A stunning view from the top of the world.Contributed

Struggling up loose shale slopes to an altitude of nearly 3000m, the sky from the deep valleys was a small patch of light among walls of green towering all round.

And a struggle it became.

"I rolled my ankle on the second day (20km into the journey) and had to walk the remaining 120km as well as I could," he said.

"There's no rescue service. You either get yourself out or you stay there".

Yet this is the countryside where a local woman was seen carrying 40kg of goods in a large back bag, held by a strap around her forehead - all in a day's work.

"I was carrying half that and it was hard enough," Ray said, recalling one rushing river crossing where water and weight held him under as he hung on to a rope to fellow trekkers in the shallows. By the end, his feet had started to rot, costing a layer of skin.